Abstract.A new experimental setup called FLASH (THErmal Fatigue by LASer or Helium pulses) has been developed to perform thermal fatigue tests on materials used in structures of Sodium-cooled Fast Reactors (SFRs). A set of thermal loadings ranging from 150°C to 200°C prescribed by a high energy laser has been applied to A316L(N) stainless steel samples. Thermal fatigue tests are performed until a macrocrack is formed. The 3D displacement fields of the surface impacted by the laser beam are measured by a hybrid multiview system. A thermomechanical model is used to compute displacement fields that are compared with correlation measurements. These results are compared in terms of strain levels to the fatigue curve determined from standardized isothermal uniaxial mechanical fatigue tests.